The aim of this study is to compare the corneal endothelium of type 2 diabetic patients with the corneal endothelium of non-diabetic controls. It has been hypothesized that oxidative and osmotic stress from excessive activation of the polyol pathway and accumulation of sorbitol may contribute to corneal endothelial damage in patients with diabetes mellitus. Previous studies of the corneal endothelium in humans have found conflicting evidence of the effect of diabetes mellitus on the corneal endothelium.

Methods

Type 2 diabetic and non-diabetic adult patients were recruited from the Montefiore ophthalmology clinic. Patients who have had a history of past intraocular surgery or corneal endothelial disease, pregnant women, women in labor, patients in significant pain, patients with altered mental status and patients who are unable to provide informed consent were excluded from the study. Specular microscopy was used to measure endothelial cell count, central corneal thickness, coefficient of variation and pleomorphism. The two sample populations were compared using independent sample t-tests.

Endothelial cell density was lower in diabetic patients compared to controls with a statistically significant p value of 0.038. The differences in CCT, coefficient of variation and pleomorphism were not statistically significant between the sample populations. The results suggest that diabetes mellitus may have deleterious effects on the corneal endothelium. The polyol pathway, often implicated as an important contributor to oxidative and osmotic stress in the setting of diabetes, likely plays a role in diabetic corneal pathology. Topical aldose reductase inhibitors may be useful in limiting damage to the corneal endothelium from diabetes.